The Flow Cytometry Core Facility (FCCF) at H. Lee Moffitt Cancer Center & Research Institute was established in 1990 to provide a centralized flow cytometry service for Cancer Center members and University of South Florida faculty with cancer related research interests. Flow cytometry is an indispensable analytical tool for cell biology, immunology, and translational research efforts at the Cancer Center. This technology provides a means for rapidly and accurately analyzing multiple characteristics of biological particles, as well as the ability to rapidly isolate and purify cell populations of interest for the purpose of assessing immunological function and molecular distinctions, cell culture cloning, and animal transplantation studies. The FCCF is staffed with highly trained instrument specialists with a combined 21 years of researchbased flow cytometry experience. The facility houses five benchtop analyzers, two high-speed cell sorters, a bead array analyzer, an automated bead sorter, and a fluorescent microscope. The FCCF provides several services including multi-parameter analysis, cell sorting, data analysis and graphics programs, instrument training, project consultation, flow cytometry courses, and application workshops. It also houses a current literature base including cytometry journals and textbooks; vendor information on instrumentation, reagents, and services; and handbooks on flow cytometry-based methodology, procedures and techniques. Overall usage in the FCCF has increased more than 180% since the 2000 CCSG submission as a result of investigator recruitment, increased instrument capacity, and the initiative to train users to operate the benchtop cytometers, which allows them unlimited independent access. Over 39 peer-reviewed investigators across all research programs routinely access the FCCF, totaling 88% usage of acquisition service, 85% usage for cell sorting, and 80% of service training. Usage is expected to grow with investigator recruitment over the next few years. The Core Facility provides critical support for the scientific programs at the Cancer Center by giving investigators access to state-of-the-art instrumentation, cutting-edge cytometry applications, and exceptionally trained staff committed to contributing to outstanding scientific research efforts to understand and control cancer biology.